For fish health, plant health, and algae control, it's important to control the pH (acidity or alkalinity) of pond water. For fish health, it's important to make certain chlorine levels are minimal for water used to fill or top off ponds.
PH CONTROL: For optimum fish health, it is important to measure buffering and pH levels periodically, and then add pH increasing salts, pH reducing salts, and buffer as needed. A 32 ounce bottle of buffer treats 8000 gallons, a 32 ounce bottle of pH reducing salts treats 32,000 gallons, and a 10 ounce bottle of pH increasing salts treats 5000 gallons. Always adjust pH before adding buffer.
DECHLORINATOR: This dry chemical reduces chlorine and chlorine by-products in tap water to levels safe for aquatic life. Add it to new ponds or ponds that have been cleaned and refilled. An 8 ounce bottle treats 45,000 gallons which is a lifetime for many backyard ponds and quite a bargain compared to liquid dechlorinators.
Buffer, 32 oz - $15.20
pH Salts Down, 32 oz - $15.80
Dechlorinator, 8 oz - $8.80